Tuesday, 8 August 2017

Asteroid 2011 CC22 passes the Earth.

Asteroid 2011 CC22 passed by the Earth at a distance of about 5 920 000
km (15.4 times the average distance between the Earth and the Moon, or 3.96% of the distance between the Earth and the Sun), slightly after 7.20
am
GMT on Friday 4 August 2017. There was no danger of
the asteroid hitting us, though were it to do so it would have
presented a significant threat. 2011 CC22 has an estimated
equivalent
diameter of 120-380 m (i.e. it is estimated that a spherical object
with
the same volume would be 120-360 m in diameter), and an object of this
size would be predicted to be capable of
passing through the Earth's
atmosphere relatively intact, impacting the ground directly with an
explosion that would be 60 000-1 500 000 times as powerful as the
Hiroshima
bomb. Such an impact would result in an impact crater about 4-5 km in
diameter
and devastation on a global scale, as well as climatic effects that
would last decades or even centuries.

2011 CC22 was discovered on 6 February 2011 by the
University of Arizona's Mt. Lemmon Survey at the Steward Observatory on Mount
Lemmon in the Catalina Mountains north of Tucson. The designation 2011 CC22
implies that the asteroid was the 1103rd object (object C22) discovered in the first half of February 2011 (period 2011 C).

2011 CC22 has a 434 day orbital period and an eccentric orbit
tilted at an angle of 34.8° to the plane of the Solar System, which
takes it from 0.99 AU from the Sun (i.e. 99% of he average distance at
which the Earth orbits the Sun) to 1.25 AU from the Sun (i.e. 125% of the
average distance at which the Earth orbits the Sun). It is therefore
classed as an
Apollo Group Asteroid (an asteroid that is on average further from the
Sun than the Earth, but which does get closer). This means that close
encounters between the asteroid and Earth are extremely common, with the
last having occurred in February this year and the next predicted
in July 2023. As an asteroid probably larger than 150 m in diameter
that occasionally comes within 0.05 AU of the Earth, 2017 MB1 is also
classified as a Potentially Hazardous Asteroid.

About Me

Studied Palaeobiology & Evolution at the University of Portsmouth, Geosciences via the Open University & Ecology and Conservation at Christchurch University, Canterbury.
Have worked in wildlife based tourism, mineral exploration, development, conservation, education & environmental chemistry. Occasionally write articles for papers and magazines.

This Blog would be impossible without the work of countless scientists (and others) throughout the world. Where possible I do my best to credit them, but there will always be many more who remain unmentioned; this does not imply I am ungrateful for their contributions. Any errors or inaccuracies are, of course, my own.